This invention relates to drain plug assemblies for use in dishwashers, and the like. Typically, dishwasher systems provide a sequence of wash, rinse and drain cycles. The drain cycle releases the wash water from the dishwasher, and fresh water is then introduced into the dishwasher to begin the next sequence of cycles.
A drain plug assembly is employed to release the wash water from the dishwasher, and it is controlled by a solenoid which is actuated by a timer. The drain plug is simply lifted by the solenoid and then reseats by gravity following release of the used washwater. It is, of course, imperative that when the drain plug reseats, a positive shut off is obtained.
Dishwasher systems also employ chemical injection pumps and recirculation pumps to supply water and other components such as detergent, sanitizing chemicals and rinse additives to the machine. These pumps are also controlled by the timer to insure that the rinse additive, detergent and sanitizer solutions are supplied during their respective cycles in correct amounts along with the water. Since the amount of water and the other components must be present in the dishwasher in controlled quantities, the water level in the dishwasher must be accurately controlled. However, if the drain plug does not seat or reseat properly, water levels cannot be accurately maintained, and the sanitary washing capabilities of the system will be compromised. Hence, the amount of chemical solution, and the water level in the machine are critical to a sanitary wash.
Typical drain plug assemblies are disclosed in U.S. Pat. Nos. 1,963,685; 2,276,670; 2,764,385; 2,879,026; 3,703,189; 4,351,355; and; 4,437,487.
Many problems caused by drain plug assemblies in dishwashers are due to misalignment of the drain plug in the drain pipe of the dishwasher system. This results in uneven wear of the drain plug and necessitates a premature replacement. Also, reduced water levels will occur due to leakage, and, as indicated, this will lessen the effectiveness of the dishwasher.